diff --git a/changelog.md b/changelog.md
index 45176fa..1fbbd80 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 2026-01-20 - 1.15.3 - fix(tests(nanonets))
+allow '/' when normalizing invoice strings in tests
+
+- Adjust regex in test/test.invoices.nanonets.ts to preserve forward slashes when cleaning invoice values
+- Changed pattern from [^A-Z0-9-] to [^A-Z0-9\/-] to prevent accidental removal of '/' characters in invoice identifiers
+
 ## 2026-01-20 - 1.15.2 - fix(dev-deps)
 bump devDependencies @push.rocks/smartagent to ^1.6.2 and @push.rocks/smartai to ^0.13.3
 
diff --git a/test/test.invoices.nanonets.ts b/test/test.invoices.nanonets.ts
index 9afee1e..648bb29 100644
--- a/test/test.invoices.nanonets.ts
+++ b/test/test.invoices.nanonets.ts
@@ -310,7 +310,7 @@ function extractInvoiceNumber(s: string | undefined): string {
     const match = clean.match(pattern);
     if (match) return match[1];
   }
-  return clean.replace(/[^A-Z0-9-]/gi, '').trim() || clean;
+  return clean.replace(/[^A-Z0-9\/-]/gi, '').trim() || clean;
 }
 
 /**